Theodosians a sect of dissenters from the Russo-Greek Church, who separated some years since from the Pomoryans, partly because they neglected to purify by prayer the articles which they purchased from unbelievers. They are noted for their honesty and strict observance of the Sabbath. An early Protestant sect bearing this name was formed in Russia in 1552 by Theodosius, one of three monks who came from the interior of Muscovy to Vitebsk, a town in Lithuania. These monks condemned idolatrous rites, and cast out the images from houses and churches, breaking them in pieces, and exhorting the people, by their addresses and writings, to worship God alone, through our Lord Jesus Christ. The inhabitants renounced idolatry, and built a church, which was served by Protestant ministers from Lithuania and Poland.
Roman emperor, whose services to the State and the Church earned for him the title of "the Great," was descended from an ancient family, and born about A.D. 346 at Cauca or at Italica, in Spain. His father was Comes Theodosius, the soldier who restored Britain to the empire. He was trained in the camp of his father, and entered on a military career, approving his talents in a campaign in Moesia in 374, where he defeated the Sarmatians; but he renounced his brilliant prospects when the emperor Gratian caused the elder Theodosius to be beheaded at Carthage in 376, and retired to his estates, where he engaged in agricultural pursuits. The incursions of the Goths soon rendered his services necessary in the field. Gratian called him to fill the place of his colleague Valens, who had fallen at Hadrianople, and he was proclaimed Augustus Jan. 19, 379. He received the government of the East. His conduct of the war was distinguished by the prudence with which he handled the dispirited troops, so that victory was gained without the fighting of pitched battles. On his return he passed through a severe sickness, and, in the belief that his end was near, received baptism at the hands of Ascolius, the orthodox bishop of Thessalonica. His baptism was followed, Feb. 28, 380, by an edict which imposed the Nicene Creed on his subjects as the faith of the land. Other laws, having regard to the improvement of morals and the welfare of the State, followed on his restoration to health. The Goths were subdued in successive campaigns, and admitted into the empire as allies.
At the time of the accession of Theodosius, Constantinople was the principal seat of Arianism. Demophilus, the Arian prelate, preferred to resign his dignities rather than subscribe the Nicene Creed, and Gregory of Nazianzum was invited to become his successor. He declined the place, but induced the emperor to deprive the Arians of the possession of all churches and other property, and to expel them from the metropolis. The Eunomians experienced similar treatment. The Manichaean heresy was made punishable with death after the Second AEcumenical Council had, in 381, confirmed the Nicene Creed and condemned all heretics. Theodosius also exempted bishops from obedience to the civil tribunals; and to his reign belongs the infamy of first establishing inquisitors of the faith. Measures were also taken to prevent the sacrifice of bloody offerings and the practice of augury among the adherents of heathenism, which induced such votaries to Satire from the cities to more distant and unimportant places. This gave rise-to the terms pagan and paganism in popular usage when speaking of the polytheistic religions.
In the year 385 the princess Pulcheria died, and soon afterwards the empress Flacilla, panegyrics being pronounced in their honor by Gregory of Nyssa; and in the following year Theodosius married Galla, the sister (f Valentinian II, emperor of the West. The latter with his mother, was expelled from Italy in 387 by Maximus, the usurper who ruled in Spain, Gaul, and Britain; and Theodosius, after he had heard that Maximus favored the pagans, marched against and defeated him. He entered Rome on June 13, 389. In 391 occurred the famous incident inwhich Ambrose, the archbishop of Milan, forbade the emperor to enter his church, and required of him the acknowledgment of his guilt in having delivered over to death 7000 (chiefly innocent) inhabitants of Thessalonica, in retaliation for the murder of his governor, Boteric. The emperor laid aside the insignia of his rank, and entreated pardon for his great sin before the congregation in the Church of Milan; and he issued an edict by which an interval of thirty days was fixed between every severe sentence and its execution.
The affairs of the Western Empire were at length settled, and Valentinian re-established on the throne, so that Theodosius was at liberty to return to his own capital. On the way, he delivered Macedonia from the robbers who lurked in its forests and swamps, and entered Constantinople in November, 391. Valentinian, however, was slain on May'15, 392, probably at the instigation of Arbogastes, a soldier of Frankish race, whose influence with the army made him more powerful than his lord. Eugenius, a learned rhetorician and skilful courtier, the mere instrument of Arbogastes, became emperor. Theodosius met the usurper in the plains of Aquileia, and achieved a victory which destroyed both Eugenius and Arbogastes, and secured the submission of the West. Four months later Theodosius died, Jan. 17, 395, of dropsy. His body was brought to Constantinople, and buried in the mausoleum of Constantine the Great.
See Zosimus, Hist. lib. 4 passim; Claudian, L. Seren. 50 sq.; De IV Cons. Hororii, etc.; Pacatus, Panegyr. Theod. Aug.; Themistius, Oratt. 5, 6, 16, 18; Sozomen, Hist. Eccl. lib. 5, 7; Socrates, lib. 5; Theodoret, Hist. Eccl. lib. 5; Ammianus Marcellinus, lib. 22:29; Jerome, ad an. 379, and De Viris Illustr. 133, 103; Ambrose, Epp. 17, 21, 27, 28, 51, 67, etc.; id. De Obitu Theod. passim; Idathius, Chronicles p. 10 sq., and Fast. p. 110; Orosius, lib. 7; Cod. Theod. passim; Augustine, De Civitate Dei, lib. 5; Rufinus, Hist. Eccl.'II, vi; Prosper, Chronicles; Cedrenus, p. 552 sq.; Greg. Naz. Carm. p. 21; id. Orat. 25; Theophanes, p. 105 sq.; Libanius, Orat.pro Templis, ed. Reiske; Symmachus, Epist. 10:17 sq.: Greg. Nyss. Opp. tom. 3, ed. Paris; Evagrius, Hist. ccl. 1, 20; Eunap. AEdes, c. 4, p. 60 sq.; Paulin, Vita Ambros. c. 24; Philostorgius, II, 11; Ambrose, De Valent. Obitu Cons. p. 1173. Also Flechier, Hist. de Thiodose le Grand (Paris, 1680, 8vo; Tillemont, Hist. des Empereurs, vol. 5; Gibbon, ch. 4 and 5; Baumgarten, Allgem. Wfelgesch. (Halle, 1754) vol. 14; Muller [P. E., Comment. Hist. de Theodos. (Gött. 1797 sq.); Rödiger, De Statu Paganorum sub Imp. Christianis; Suffken, De Theod. M. etc. (Lugd. 1828); Pauly, Real-Encyklop. s.v.; Ullmann, Gregory Naziam (Darmst. 18- 25); Olivier, De Theod. M. Constitutionibus (Lugd. Bat. 1835); Schröckh, Christl. Kirchengesch. vol. 7; Gieseler, Kirchengesch. vol. 1; Smith, Dict. of Biog. and Mythol. s.v.; Herzog, Real-Encyklop. s.v.